Injection device



y 1935- w. HERRMANN 2,006,572

INJECTION DEVICE Filed Aug. 24, 1933 Jnventor:

Patented July 2, 1935 I I UNITED STATES 1 PATENT OFFICE INJECTION DEVICE Walter Herrmann, Dresden, Germany Application August 24', 1933, Serial No. 686,507

In Germany October 7, 1932 3 Claims. (01. 103-9) This invention relates to an injecting device for According to the construction of this intermeinternal combustion engines for delivering two diate piston, injection of theadditional fuel may different fuels insuccessive pipings independently be effected before the driving oil is injected to from one another to the point of injection. favor ignition after the injection of the il Injectingdevices for internal combustion ening oil to wash out the injection nozzle. To ful- 5 gines for delivering two fuels, e. g. for burning tar fill the latter purpose the intermediate piston is oils or alcohols that are not readily spontaneously preferably of the differential or multiple stage inflammable by means of easily inflammable gas type. oils are known already. It is further known to One form of the invention is illustrated on the employ a'separate pump for injecting each fuel,'- accompanying drawing, in which Figure 1 is a 0 each pump having either a special mechanical diagrammatic view of the device for injecting the drive, or the ignition oil pump is hydraulically additionalfuel prior to thedriving oil; and Fig. driven by the driving oil pump to save the me- 2, a view of a device in which the additional fuel chanical driving means. The invention has to do is injected after the driving oil has been injected.

with the latter kind of drive. In the known de- Referring to the drawing, in the working cyl- 1b vices, the 'piston of the ignition oil pump isv inder l operates the piston or plunger 2. 3 isthe either plain or of the differential type and moves combustion space or hot bulb. Supply of drivin a cylinder communicating with the working 'ing .oil is effected by a main pump consisting space of the driving oil pump between the suction mainly of a housing 4 and the piston 5 working 30 and pressure valves. In order to make the ignitherein. Drive of the piston 5 is effected by a tion oil pump deliver before the driving oil pump, cam disc 6 and the guide roll 1 moving thereon. the pressure valve of the latter is loaded so that The fuel flows through the piping 8 opening into it will open only when the piston of the ignition; the housing 4 to the main pump. At the inlet oil pump, at theend. of its pressure stroke, is pointavalve 9 is provided, and the housing4 con- 2 prevented from further motion by a stop and the tains also a regulating valve In which is condriving oil pressure increases still more under trolled by the shaft ll actuator by the regulator the influence of further motion of the driving oil in order to adapt the fuel supply to the main piston. It happens, however, in connection with pump to the motor load. From the housing 4 a such pumps that, if the ignition nozzle is slightly delivery piping 12 leads to the auxiliary pump clogged, the pressure of the driving oil required housing l3 in which the intermediate piston I4 30 for moving the ignition piston will be higher than Operates in a closely sliding manner. At a certhe pressure at which the pressure valve of the tain distance from the inlet point l2 the auxiliary driving oil pump will open, so that the ignition housing I3 is connected with another portion of oil pump fails to operate while the driving oil the delivery piping l5, a regulating valve l6 being pump continues to work. The tar oil which does provided at thepoint of junction. The piping 35 not burn for lack of ignition oil will then soil the IS leads directly to the point of the injection in engine cylinder and the piston will grind. the hot bulb 3. By a compression spring [1 the The known devices further fail to solve the piston I4 is constantly pressed into end position, problems connected with the use of thick oils in which it prevents the flow of fuel to the piping 49 which often coke the nozzles and which make it IS. Into the other end of the cylinder l3 opens necessary to wash the nozzles with good oils or a delivery piping l8 for additional or auxiliary alcohols at the completion of injection to purifuel, a regulating valve l9 being interposed at the fy the exhaust, which is done by air in Diesel enpoint of junction. 20 is the piping for liquid fuel, gines having a compressor. which at 2| branches out into the pipings 22 and The invention eliminates the drawbacks of the 23. According to the position of the member 2 I, 45 known devices by providing a main pump for injection of the auxiliary fuel may be efiected the driving medium, in the delivery piping of through the piping 22 opening directly into the which a housing constructed as pump cylinder is cylinder or the fuel is delivered through the pip-' interposed. In the housing is found a piston ing 23 to the main piping l5 and injected there e controlled by the liquid pressure of the main before the driving oil through the hot bulb 3.

pump and releasing delivery of the driving oil At the point of junction of the piping 20 and the towards the point of injection only after having housing 13 a regulating valve 24 is disposed. 25 carried out part of its motion, whereas on the is a screw spindle which can be turned more or other side of the piston a supply and discharge less into the cylinder for Varying the stroke of piping for additional fuel are provided. the piston it. There is also a connecting piping 55 26 which connects the main supply piping 8 with the piping l8. At the point of junction a control valve 21 is arranged by the actuation of which the pipings l8 or 8 may be alternately connected with the auxiliary pump.

The device described functions as follows:

Owing to the turning of the cam disc 6, the piston is moved up and down in its housing 4, fuel drawn outof the piping 8 and pressed into the cylinder l3 before the piston I4 which is thus displaced against the action of the spring l1. After the piston I4 has carried out part of its stroke, the discharge piping I5 is exposed, so that the valve l6 opens and delivery of the driving oil I through the piping l5 to the point of injection can take place. When the piston 5 begins its suction stroke, the piston M will be pressed back by the spring I! and the auxiliary fuel in the cylinder l3 drawn in from the piping 18 while the valve I9 is open. At a new pressure stroke of the piston 5, the piston M will be pressed forward and the auxiliary fuel drawn into the cylinder I3 guided through the pipings 20 or 22, 23 to the point of injection. Only after the piston I! has released again the junction point of the piping [5 can injection of the driving oil be effected after the auxiliary fuel has been injected.

In the construction shown in Fig. 2 the auxiliary fuel is injected only after the driving oil. For this purpose, the cylinder I3 has a narrow portion 21a and a wider portion 28. Correspondingly, the piston H is formed by a part 29 of smaller diameter and a part 30 of larger diameter. The delivery piping l5 and the piping I2 open into cylinder portion 21a in the same way'as into the cylinder l3 shown in Fig. 1, but the pipings I8 and 20 are connected to one end of the wider cylinder part 28.

This device functions so that at the pressure stroke of the piston 5 of the main pump the piston 29, 30 is pressed forward, the auxiliary fuel being drawn out of the piping l8 by the piston portion 30. When the piston portion 29 has released the point of junction for the main piping 15, delivery of the driving oil takes place, partly under the pressure of the main pump. After delivery, the piston 29, 30 returns to initial position by means of the spring I! while the piston portion 30 passes the auxiliary fuel contained in the cylinder 28 through the piping 20 to the injection point where it serves for washing the injection nozzle.

The two pumps may be used alternately by controlling the supply and discharge pipings through the regulators 21 and 2|. Furthermore, the device may be used also as starting pump for precombustion chamber engines, in which the fuel, in the beginning or continually, is fed to an ignition nozzle in the cylinder space. The gradual injection of the fuel or a. corresponding combustion insures steady running of the engine, especially during starting. 'Vigorousturbulent motion of the fuel insures high power effect during starting. The device .can be advantageously used where fuel has to be successively injected through several nozzles into the combustion spaces oi an engine. Furthermore, the device according to the invention combines greatest simplicity in design with cheapness and clear operation, and can be attached to existing engines, no matter whether closed or open nozzles are concerned. The device can further be of the double-acting type.

I claim:

1. Injection device for internal combustion engines, comprising a main pump for the driving medium, a delivery piping connecting the pump with the point of injection, a housing constructed as pump cylinder and interposed in said delivery piping, a piston controlled by the liquid pressure of the main pump and arranged in said housing, said pistdn releasing only after part of its motion with its front side said delivery piping for driving oil towards the point of injection, a supply piping for auxiliary fuel opening on the rear side of said piston into said housing, a discharge piping for auxiliary fuel opening into said housing on the same side and leading towards the point of injection, a compression spring for bringing said piston into end position in which it shuts 01f the delivery piping for the driving medium, and regulating valves disposed at the points where said pipings open into said housing.

2. Injection device for internal combustion engines, comprising a main pump for the driving medium, a delivery piping connecting the pump with the point of injection, a multiple housing interposed in said deliver ing, a piston controlled by the liquid pressure of the main pump in one part of said housing, said piston releasing only after part of its motion with its front side delivery piping for driving oil towards the point of injection, an additional piston on the second part of said housing, said piston being rigidly connected with said first piston, a supply piping for auxiliary fuel opening at the front side of said second piston into said second part of the housing, a discharge piping for auxiliary fuel opening at the same side into the same house portion and leading towards the point of injection, a compression spring, said spring bringing the said two rigidly connected pistons into end position in which the delivery piping for the driving of connection between said delivery piping and the two housing portions.

3. Injection device for internal combustion engines according to claim 2, in which the two pistons in the housing interposed in the driving medium delivery piping form a multi-stage piston.

WALTER HERRMANN. 

